Drawbar for tractors



NOV. 10, 193 1. Q HE D 1,830,874 v DRAW BAR FOR TRKCTORS Filed March 13. 1929 FIG-.7

' INVENTOR. Foami- 0. f/f/VDfi/CASO/V A TTORNEY Patented Nov. 10, 19 31 ROBERT O. EENDBICKBON, OI BACINE, WISCONSIN, ASSIGNOR T J. I. CASE COMPANY,

- OF RACINE, WISOONSIN, ..A CORPORATION DBAWBAB FOR TBAOTOBS Application fled larch 13, 1939. Serial No. 346,750.

My invention relates particularly to a tractor drawbar which may be automatically locked when a tractor is pushing its load rearwardly, my object being to provide Li means whereby the drawbar is automatically prevented from buckling,,.or pulling sidewise, and also means permitting the drawbar to freely swing radially without undue -wear on parts associated therewith; and a further object is to so couple a serles of tractors as to eliminate transmission of the pulling power directly through the frames of the various tractors in the series, and reduce the tensional strain therebetween to a negligible degree, as will hereinafter more fully appear.

In the operation of self-propelled vehicles, such as tractors and the like, it is well known that when the tractor is pulling a load the 0 drawbar thereof freely swings radially om its pivotal point to compensate for the turning action of the tractor in relation to the pulled implement or load as the tractor turns corners. When a tractor is pushing an 1m- 35 plementattached thereto, that is, moving 1t rearwardly, as becomes necessary at tlmes durin plowing operations when it is require to release the plow, from immovable obstructions such, as hidden stones or roots,

the tendency; of the drawbar is to buckle or jack-knife upon itself so that parts thereof become bent or twistedout of shape unless suitable provision is made to lock the drawbar in stationary position. It is quite common to employ a number of tractors..c0n nected in series or tandem for pulling ex tremely heavy loads, in which circumstances it is well known that those tractors at the rear of the series are subject to undue tensional strain from the pull of the fore tractors transmitted through the frames of the succeeding tractors to their respective draw bars.

In the accompanying'drawings, forming part hereof, Figure 1' is a plan view of a tractor showing my improved drawbar attached thereto; Fig. 2, an enlarged side elevation of my improvement, partly in section, the drawbar bein broken to reduce the structure in length for e purpose of showing the parts associated therewith, and Fig. 3 is a fragmentary view of the guide as seen when looking forwardly from behind the tractor.

In said drawings, the portions marked 5 indicate the body of a tractor, to which the front wheels 6 and the rear wheels 7 are atfree to move longitudinally and forwardly as the tractor moves backwardly against a resisting element. Abracket 15 is securedto the'rear end of the drawbar, at 16, said bracket having an upturned member 17 constituting a bearing for a roller 18, which latter is rotatably mounted u on a bolt 19, the forward end. of thebolt eing tapered for a purpose to appear, said bracket and roller constituting a carrier for conducting the drawbar along the guide. I The roller 18 transmits the weight of the drawbar to guide 9, 10, and, as indicated, rotates on the bolt 19 as the rear end of the drawbar swings laterall on the guide'in ahorizontal directlon, w en a tractor draws in pulls an im plement or the like, due to inequalities in the draft of such implement, and, as said roller is free to rotate, it will be understood that friction between and wear of the parts is materially reduced. In the upright memher 9 .of the guide I rovide a series of holes 21, as indicated in Fig.3, so that as the tractoris moving backwardly against reslstance .the tapered end 20 of the bolt 19 will enter one of the series of holes 21 and engage therewith and thus. lock the drawbar in fixed position so lon as the rearward motion is continued, as mdicated by the dotted lines 22in Fig; 1.

Inthe horizontal leg 10- of the guide I provide a series *of holes 23 for the pur lose of 1 locking the drawbar 12 at any desire angle or plns tion to compensate for side draft when pu 'ng implements'such as harvesters, binders and the like, which is accomplished by ini I serting bolts or pins 23' into said holes 23 at each side of the drawbar by which means the latter is prevented from swinging laterally in either direction but which may be shifted longitudinally between the pins.

In the front end of drawbar 12 a hole 24 is provided through which a chain or rope 25 can be fastened, the opposite end of which chain or rope is attached to the drawbar 15' of the preceding tractor, by which means I am enabled to connect a series of tractors together to pull one load, thus eliminatin transmission of the tensional pull throng the respective frames of the tractors as is now common and resulting'in distortion of the frames and misalinement'of the tractor bearings.

Y I claim as my invention:

The combination, with a tractor, of supports secured thereto, a guide immovably mounted on the supports, a drawbar pivotally connected to the tractor adapted to be shifted longitudinally and swung laterally in relation thereto, a carrier embodying a roller associated with the drawbar and adapted to travel along said guide as the drawbar is moved laterally in-relation to the guide, said'guide having means whereby when the tractor is moved rearwardly the carrier will become engaged with and prevented by the guide from moving laterally and also whereby when the tractor is moved forwardly the carrier will be released from engagement with the guide so that the drawbar will swing laterally inrelation thereto.

In testimon whereof I afiix my signature.

ROB RT 0. HENDRICKSON. 

